Honda ATV Forum banner

1 - 10 of 10 Posts

·
Super Moderator
Joined
·
4,389 Posts
Discussion Starter #1
Alright i got my 300ex going a running good finally and i figured i would have to rejet so my brother had the stock jet out of his 400ex a 148 so just for kicks i put it in just to see how far off it would be. I did a plug check and its not far off. I have good throttle response good when i really rip on it but when im just running around the yard not putting but not hammering on it like in the mid it kinda falls on its face for a split second. I just installed a new clutch so its not that. Its gotta be my jetting im running a 40 or 42 pilot 148 main and my needle is at stock setting right in the middle. Any help is greatly appreciated.
 

·
Super Moderator
Joined
·
4,389 Posts
Discussion Starter #2
Ok i rode it around some more just now and it smells way rich. The plug is black and im starting to think a 148 was just dumb lol. Im gunna try some smaller ones prolly a 146 or 144.
 

·
Super Moderator
Joined
·
18,227 Posts
I would say a 140 is going to be the closest guess I can come up with? Have you internally modded the engine? I can't remember? If you put a 400EX carb on you can use that 148 main and 38 slow...lol

FYI just putting around the yard isn't going to have any bearing on the main jet. your slow jet is too big. does it sputter when you shift to 2nd and not get on it?
 

·
Super Moderator
Joined
·
4,389 Posts
Discussion Starter #4 (Edited)
Nope only sputters when im between wot and putting around i guess closer to wot than idle though. And yes i put a stage 1 webcam. Besides that i put a stock crank in it so that wouldnt effect it. And no it dont sputter when i shift from first to second. It only really sputters when i get on it. I guess and it smells really rich. I had a 140 in it and it was lean. Im thinking like a 142 or a 144 possibly even a 146 but a 148 is alittle much i think.
 

·
Super Moderator
Joined
·
18,227 Posts
One thing to check then is the clip on the needle. mine did the same thing and come to find out the clip was bent a little and loose feeling so the needle wasnt seating properly. the main only functions past 3/4 throttle so I think your issue lies between the slow jet and needle.
 

·
Super Moderator
Joined
·
4,389 Posts
Discussion Starter #6
K my needle is on the stock setting or in the middle could my mixture screw b a problem my brother set it at 2 3/4 and i havent touched it. And if i recal the clip was a little loose on the needle when i changed it bad to stock. If it is loose how do i fix it buy a new needle or clip or both? Im starting to think about just getting a jet kit and being done with it. Is that a good idea.
 

·
Super Moderator
Joined
·
18,227 Posts
The needle should be fine it's the clip that you will need to replace.... they are very thin and easily bent. you may just get by with finding the clip maybe the dealer has them. the pilot setting may be a bit lean I would turn it in to seat then back it out 3 turns that should be rich enough on that setting. I would also put a 38 slow jet back in along with the 140 main. Do a good hot run on a new plug and take a plug reading, if it's too rich drop the main to a 135 or 136. All the mods on my quad I only ran a 134 and 38 slow it ran perfect. I have since put on a 400EX carb.
 

·
Super Moderator
Joined
·
4,389 Posts
Discussion Starter #8
Ive been thinking about putting on a 400ex carb to where does that get me jetting wise and how big of a upgrade is it power wise? Anything i need to make it fit? I may just ditch this carb and buy my brothers extra carb for his 400
 

·
Registered
Joined
·
2,735 Posts
More air flow gives you a boost in power.As for jetting I'd say a 140 would be close.
 

·
Super Moderator
Joined
·
4,389 Posts
Discussion Starter #10
I just dont understand how im running a 148 rightnow without any smoke and its only alittle rich when i pull the plug. I mean alittle richer than i like so im gunna change it but i would think a 148 would be way off. Like black smoke all the time bogging all the time way off. Could the mixture screw being 2 3/4 turns out be the cause of this or do you guys think something else isnt right. I know my brothers staror just went bad on his 400ex and it was running a jet that dosnt make sense then when he got a new stator his jets had to go back to where we thought they should be. Is my jetting a sign of problems to come?
 
1 - 10 of 10 Posts
Top